Liquid filling apparatuses are well known in the art. They are in widespread use for, for example, filling containers for storage of milk, juice and the like. Many of the processes in such filling apparatuses are carried out in an automated manner. That is, the containers are erected and positioned within a filling area, the containers are filled, and the containers are then sealed by automatic operation of the apparatus.
In an effort to reduce the contamination of food product, and to provide product having a relatively extended shelf life, many such filling apparatuses operate in hygienically clean or aseptic environments. The equipment used in such hygienic processes must be maintained and operated in a clean, hygienically approved condition.
These liquid filling apparatuses have also undergone improvements relative to the speed at which they operate. Such apparatuses are known to package up to about sixty (60) one-liter containers per minute. The combination of strict cleanliness and operating speed can put extreme constraints on the equipment and materials of construction. In particular, the moving parts of the apparatus that come into contact with the liquid food product, and more particularly, the non-metallic components, can be subjected to high stresses.
One particular portion of the apparatus, the filling valve, can be subjected to localized high stresses and can require frequent maintenance and repair. The soft, flexible, non-metallic, moving portions of the valve, such as the valve cone, can require frequent repair or replacement. The valve cone is that portion of the valve that forms a seal against the harder, typically steel valve seat.
In a common configuration, the cone is formed of a high grade silicone or like material that can be made to governmental (e.g., FDA) or industry hygienic standards. The cone is actuated by a stem that extends into the valve body from about an end thereof, and connects to the cone at about the top of the cone. As the cone is moved from the closed position to the open position, it is pivoted downwardly in an arcuate motion by the stem, into the valve body, toward a side wall of the valve. When in the open position, the valve cone rests near the side wall, which reduces the amount of space available for maintaining and cleaning the valve. Such reduced maintenance space can increase both the time and the cost associated with equipment maintenance.
In addition, in such known valves, the cone portion that comes into contact with the liquid food, is sealed from the environs by a cone shield. The cone shield is a flat, planar member mounted to, and surrounding the stem. In a known apparatus, the shield is mounted perpendicular to the longitudinal axis of the stem. The cone serves as a sealing element, and is formed of the same material as the cone (e.g., high grade silicone) in the event that it comes into contact with the liquid food product.
The shield rests against an outer surface of the valve body. As the valve cone pivots between the opened and closed positions, the shield flexes to remain in contact with the valve body, while accommodating the pivoting stem. As such, the shield can be subjected to high localized stresses, and because of the nature of the material, can fail due to fatigue of the material. In particular, failure has been observed in the region of the shield adjacent to the stem. Fatigue failure has been noted to increase with an increase in the angle or distance that the valve cone pivots.
Moreover, because of the "top-entry" nature of known valves, it has been necessary to use differently designed valves for each the inlet and outlet sides of the filling pump. This is principally due to the interference that the top-entry assembly causes with the food product flowing from the pump discharge. Furthermore, because the actuator is of the top-entry design, flow resistance increases across the valve, which, in order to be overcome, requires significantly over-sized interconnecting piping and components.
Accordingly, there continues to be a need for a hygienic in-line valve for a liquid filling apparatus, which valve has a side entry configuration. Such a valve reduces the wear, fatigue and eventual failure of the non-metallic, resilient sealing components, such as the cone shield, and facilitates internal valve cleaning and maintenance. Such an in-line valve further reduces flow resistance across the valve, thereby allowing the use of an overall smaller profile valve having correspondingly smaller valve components to achieve the desired flow characteristics. Advantageously, such a valve can be used in either or both the inlet valve position and the outlet valve position relative to the filling pump.